<template>
  <div>son子组件 -- {{ value }}
    <el-button @click="changeMsg" />
  </div>
</template>

<script>
export default {
  props: {
    value: {
      type: String,
      required: true
    }
  },
  methods: {
    changeMsg() {
      this.$emit('input', '想你的夜')
    }
  }
}
</script>

<style>

</style>
